I have an aluminum boat that I painted 20 years ago and besides for the normal wear and scratches on the bottom it looks like brand new. You need to buy the right kind of paint. That would include a zinc phosphate primer and the proper paint to go over it. The primer is extremely important on aluminum. I bought mine directly from Lund boat company. They will sell you everything you need, same stuff they use. I sanded the entire boat mostly with an orbital sander with tough spots done by hand. Then I sprayed each layer, primer and final coat, one at a time with baking after each coat. I baked the paint using a kerosene powered torpedo heater. Do this by first spraying primer inside, turn the boat upside down on blocks and prime the outside. The boat should be blocked just high enough off a concrete floor that you can insert a metal duct attached to the torpedo heater to blow the heat under the boat. Since heat rises it will mostly stay under the boat and the whole boat will heat up baking both inside and outside at once. You may want to put some cardboard around some of the perimeter to keep all the heat from leaking out between the boat and the garage floor. I think I attached either cardboard or plywood to some 2 by lumber that could sit on the floor and block some of the heat in. Repeat this with the final coat. I used the rough floor paint on the inside (also directly from Lund) with the final finish coat of smooth paint on the outside. Heat the boat until it's almost too hot to keep your hand on it very long. You are looking for about 250 degrees. Keep the heat on for 20 to 30 minutes being carefull to monitor at all times and turn the heater on and off as needed to keep it hot. You will have a bulletproof coat of paint that will be one with the metal if you do all of this right. I went this route because where I worked we painted aluminum for marine use, and that's how we did it. I found that is also how Lund did their boats so I bought the whole works from them. I did a 16 foot deep vee boat with a quart of primer (it goes farther) and a quart of each interior and exterior. The whole process is not as bad as it sounds and it you really want it to last this can't be beat. I don't think even epoxy will stick unless the aluminum is acid etched or primed properly. Now since 20 years ago there might be better paint systems to use so I would contact an aluminum boat maker, find out what they use, and buy it from them. If you find like I did that it is still being baked on, then here's a method that will do it.
Last edited by bz; 03/21/10 08:41 PM.
